This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Surgical removal of brain tumors is the most common initial treatment received by brain tumor patients. Surgical resection can benefit the patients in several ways: for example, it relieves the mass effect of tumor on neurological tissue and allows histological diagnosis of the tumor, which directly affects the direction of follow-up therapeutic strategy (3). Many studies have demonstrated that aggressive surgical resection enhances the survival length and quality of life for brain tumor patients. Therefore, the goal of brain tumor resection procedures is to maximize tumor removal with minimal neurological damage. To achieve this goal accurate intraoperative identification of brain tumor margins during craniotomy is required. This study aims at the development of a means for visualizing brain tumor margins using optical techniques such as Modulated Imaging.